Develop a Maintenance Plan

The primary goal of a maintenance plan is to maintain integrity of the data collected. If you are successful in this regard, you will always be able to recover from a service interruption and continue operation with minimal or no loss of data. Since you can never ensure 100% system uptime, you must frequently and regularly back up current data and configuration files, and maintain non-current archive files in a read-only state, following the guidelines for backup and routine maintenance.

Routine Maintenance: On a regular schedule, examine and analyze the system performance indicators displayed on the System Statistics page of Historian Administrator as follows.

Table 1. System Statistics Performance Indicators
Field Recommended Action
Consumption Rate of Archive Storage If the rate is excessively high, reduce the rate at which data flows into the system or increase the filtering applied to the data to lower the rate of archiving. To reduce the collection rate, slow the polling rate on some or all tags. To increase filtering, enable compression at the collector and/or archiver and widen the compression deadbands.
Failed Writes If the display shows a significant number of failed writes, investigate the cause and take corrective action to eliminate the malfunctions. Refer to the DataArchiver-XX.log file or query the message database to determine the tags for which failed writes occurred.

For example, trying to write values to a deleted archive causes failed writes. Trying to archive data with a timestamp that precedes the start time of the first archive, trying to write to a read-only archive, or trying to write a value with a timestamp more than 15 minutes ahead of the current time on an archiver will produce a failed write.

System Alerts Not applicable

On a regular schedule, examine and analyze the performance indicators displayed in the Performance section.

Table 2. Collector Performance Indicators
Field Recommended Actions
Avg. Event Rate Chart Not applicable
Compression Chart Is compression effectiveness acceptable?

If not, verify that compression is enabled and then widen the deadbands to increase the effect of compression.

Overruns Chart If the value is anything other than zero, determine the severity and cause of the problem and take corrective action.